Vertex Calculator | Lens Power Conversion
Vertex Calculator
Effective lens power conversion

Fc = Fs / (1 − d·Fs)
Fc = new lens power, Fs = original lens power, d = vertex distance change (m)
D

Enter a valid power. This combination of power and vertex distance makes the denominator zero — no finite result exists.

New lens power (Fc)
— enter a value and solve —

The effective lens power formula (also known as the vertex distance formula or vertex power formula) for optical correction is based on the fundamental principles of paraxial optics and vergence.